Padme dies giving birth!
Leia remembers "Feelings" - "Images" - She's stronge in the force!
"A Jedi's weapon, much like your fathers" - Meaning that only Vader has the weapon of the Jedi - Luke will have Anakins Lightsabre that he uses in 3.
"That boy is our last hope" - Probably meaning that Luke has already started his traing - Leia has not. She doesn't even know she has the Force running through her. Obi just probably thought it was too late for to start training Leia, given her age!
They were hidden seperatly to protect them. Two kids strong in the Force together with Yoda is too easy to find.
And maybe Anakin didn't even know about Leia being born. - Actually he didn't know!
Well thats my thoughts on the subject anyway!!